Update constants and create 3 functions, one each for applying or

removing syntax and one specificaly for bold-italic syntax.

Author: hreikin

tkintermd/tkintermd_constants.py

@@ -16,8 +16,8 @@
 italic_md_syntax = ("*", "_")
 """tuple: Markdown syntax for italic highlighting."""
 italic_md_ignore = (
-    "**", "__", "- ", "> ", "# ", "`", 
-    "--", ">> ", "## ",
+    "- ", "> ", "# ", "`", 
+    "**", "__", "--", ">> ", "## ",
     "***", "___", "---", ">>> ", "### ", "```", "===",
     "####", "#####", "######",
 )
@@ -26,9 +26,9 @@
 bold_italic_md_syntax = ("***", "___")
 """tuple: Markdown syntax for bold-italic highlighting."""
 bold_italic_md_ignore = (
-    "*", "_", "- ", "> ", "# ", "`", 
-    "**", "__", "--", ">> ", "## ",
-    "***", "___", "---", ">>> ", "### ", "```", "===",
+    "- ", "> ", "# ", "`", 
+    "--", ">> ", "## ",
+    "---", ">>> ", "### ", "```", "===",
     "####", "#####", "######",
 )
 """tuple: Markdown syntax to ignore for bold-italic highlighting."""